Benefits and Harms of Omalizumab Treatment in Adolescent and Adult Patients with Chronic Idiopathic (Spontaneous) Urticaria: A Meta-analysis of "real-world" Evidence

Importance: Omalizumab is indicated for the management of chronic idiopathic urticaria (CIU) (also known as chronic spontaneous urticaria) in adolescents and adults with persistent hives not controlled with antihistamines. The effectiveness of omalizumab in the real-world management of CIU is largely unknown. Objective: To quantitatively synthesize what is known about the benefits and harms of omalizumab in the real-world clinical management of CIU regarding urticaria activity, treatment response, and adverse events. Data Sources: Published observational studies (January 1, 2006, to January 1, 2018) and scientific abstracts on the effectiveness of omalizumab in CIU were identified using PubMed, Embase, Web of Science, and Cochrane search engines; references were searched to identify additional studies. Study Selection: Included studies were observational in design and included at least 1 outcome in common with other studies and at a concurrent time point of exposure to omalizumab. A total of 67 articles (35.2% of those screened) were included in the analysis. Data Extraction and Synthesis: PRISMA and MOOSE guidelines were followed; independent selection and data extraction were completed by 2 observers. Random-effects meta-analyses were performed. Main Outcomes and Measures: Main outcomes were change in weekly Urticaria Activity Score (UAS7; range, 0-42), change in Urticaria Activity Score (UAS; range 0-6) (higher score indicating worse outcome in both scales), complete and partial response rates (percentages), and adverse event rate (percentage). Results: Omalizumab therapy was associated with an improvement in UAS7 scores (-25.6 points, 95% CI, -28.2 to -23.0; P <.001; 15 studies, 294 patients), an improvement in UAS scores (-4.7 points, 95% CI, -5.0 to -4.4, P <.001; 10 studies, 1158 patients), an average complete response rate of 72.2% (95% CI, 66.1%-78.3%; P <.001; 45 studies, 1158 patients) with an additional average partial response rate of 17.8% (95% CI, 11.7%-23.9%; P <.001; 37 studies, 908 patients), and an average adverse event rate of 4.0% (95% CI, 1.0%-7.0%; P <.001; any level of severity, 47 studies, 1314 patients). Conclusions and Relevance: Benefits and safety of omalizumab in the real-world treatment of CIU meet or exceed results gleaned from clinical trials. These real-world data on omalizumab in CIU may help inform both clinical treatment expectations and policy decision making.